Typical high speed Vertical Takeoff and Landing (VTOL) aircraft designs have poor hover capabilities. In contrast, helicopters are generally low-speed with high hover capabilities. High-speed VTOL designs require high-powered, heavy weight, highly loaded vertical thrust mechanisms that become dead and/or inefficient weight and lead to excess aerodynamic drag after takeoff during horizontal flight. For aircraft that take off horizontally, overly large propulsion mechanisms are required to generate enough power needed for takeoff. These overly large propulsion mechanisms reduce the efficiency of such aircraft because they add unnecessary weight and drag during cruise flight.
Stop rotor aircraft in which the rotor blades rotate as a helicopter during takeoff and landing, and lock into a position orthogonal to the fuselage, have been narrowly explored as a way to obtain hover capabilities comparable to a helicopter with the efficient horizontal flight of a winged aircraft. However, existing designs struggle to achieve a successful transition between a rotary wing and a fixed wing during flight.